liblineutils

A simple C library for text stream processing that provides three functions similar to the UNIX commands head, tail, and longlines.
This project is part of the Operating Systems course — Software Engineering Degree, 2025–26.

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🧑‍💻 Authors

Iván Pina Brox: @ivannpinna

Jaime Sánchez Vázquez: @jaimesnh

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📄 Description

This library allows you to read text from the standard input and display:

• The first N lines (head)
• The last N lines (tail)
• The N longest lines (longlines)

It is designed as a reusable C library (.a or .so) and includes a test program to verify and demonstrate its functionality.

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⚙️ Functions

int head(int N)

Prints the first N lines from the standard input to the standard output.

int tail(int N)

Prints the last N lines from the standard input to the standard output.

int longlines(int N)

Prints the N longest lines (from longest to shortest) read from the standard input.

All functions return 0 on success and -1 on error.

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🧩 File Structure

├── libreria.c # Implementación de las funciones: head, tail, longlines, etc.

├── libreria.h # Cabecera con los prototipos de las funciones

├── test.c # Programa principal: lee argumentos (-head, -tail, -longlines)

└── compile.sh # Script de compilación y generación de la librería estática